Giannis Antetokounmpo dominated from start to finish as the Bucks opened the playoffs with a win over the Raptors. (Nathan Denette/The Canadian Press)

From the moment Giannis Antetokounmpo arrived in the NBA as a fresh-faced 18-year-old from Greece four years ago, the potential for greatness oozed out of him. With unlimited athleticism and arms that seemingly stretched from coast-to-coast, he was the kind of tantalizing prospect that arrives in the NBA every so often.

And after showing steady progress through his first three seasons, he exploded into another stratosphere this year. “The Greek Freak” saw virtually all of his numbers skyrocket across the board, deservedly became an all-star starter, almost certainly earned himself the league’s most improved player award and now looks like a potential future MVP of the league.

All of that was done in the relative obscurity of Milwaukee, though, on a team that spent most of the season battling injuries and fighting for a spot in the playoffs — a spot the Bucks wound up earning in large part because of Antetokounmpo’s fantastic play. But it also meant Milwaukee entered its playoff series against Toronto a decided underdog, with the expectation that this was going to be a learning experience for a young team still trying to understand what it takes to be a contender.

That was before Saturday’s opening game of a best-of-seven affair, and before Antetokounmpo dominated from start to finish in a thorough beatdown by the Bucks of their deeper and more experienced opponents. Suddenly the idea of Milwaukee, 97-83 winners in Toronto, advancing to the second round seems quite possible. And the official emergence of Antetokounmpo as the NBA’s next superstar feels imminent.

By the time Saturday’s game was over, there was little doubt that Antetokounmpo, who finished with 28 points on 13-for-18 shooting to go along with eight rebounds, three assists, two steals and a block in 38 minutes, is the best player in this series, and by a significant margin. That’s not an indictment of Toronto’s all-star backcourt of Kyle Lowry and DeMar DeRozan, although the two of them combined to shoot 9-for-32 overall and 0-for-8 from three-point range as their playoff struggles from the past few seasons continued.

Instead, it’s an acknowledgment that Antetokounmpo’s talents comprise the rare combination that transcends what most of the league’s stars can do. His physical gifts at both ends of the court allow him to serve as a 6-foot-11 point guard for Milwaukee on offense, the become arguably the team’s best rim protector defensively. All of those qualities were on display in Milwaukee’s comprehensive victory Saturday.

In the crucible of a seven-game playoff series, having the best player — even when everything else tips the other way — can often be enough to swing a series. Saturday’s game showed that, in this case, that possibility very much exists in this series, even as the Raptors arrived as the team anointed by many to be the biggest obstacle in the Cleveland Cavaliers’ path back to the NBA Finals.

The combination of an all-star backcourt and savvy trade deadline acquisitions in forwards Serge Ibaka and P.J. Tucker left Toronto with a deep, versatile, battle-tested team, far better than the group the Cavaliers eliminated in last season’s conference finals. The Raptors also appeared to be capable of serving as the biggest threat to stop James’ run of consecutive Finals appearances at six.

That calculus left out one very crucial factor, however: to get to the Cavaliers and a presumed second round showdown, the Raptors have to take down the Bucks. But finding a way to stop Antetokounmpo and beat Milwaukee is going to be much easier said than done.

This was the definition of a coming-out party for Antetokounmpo and the Bucks, a team that last summer seemed poised to take a leap forward before Khris Middleton suffered a severe hamstring injury before training camp, then lost Jabari Parker to a torn anterior cruciate ligament just as Middleton finally got back on the court midseason.

The question now is how will the Raptors respond? Toronto has been here plenty of times before, having gone 1-11 all-time in the first game of playoff series, including a run of nine straight opening-game losses. Lowry and DeRozan have struggled before only to bounce back later, and it has to be expected they will again in this series. Milwaukee’s edge in offensive rebounding — an area Toronto should be controlling — likely won’t continue, nor should the Bucks achieving a 12-point advantage from behind the three-point line.

What will continue, however, is Antetokounmpo’s status as the series’ best player, and that could prove to be all that matters. Every game is an occasion for Antetokounmpo to do at least one thing that elicits disbelief. There was a dunk over Serge Ibaka that saw him extend his arms like Inspector Gadget to somehow get to the rim and slam it home after leaping from impossibly far away.

There was the breakaway and-one layup that saw him gather the ball just inside the three-point arc and still finish the play while being grabbed from behind by Jonas Valanciunas. There was the block of DeRozan in the game’s final minutes that left Antetokounmpo so animated that the normally mild-mannered star was hit with a technical foul.

“I was feeling the energy of the game,” Antetokounmpo told reporters after the win. “I was just excited. I’ll learn. The next time, I’ll be less excited.”

He will have plenty more chances to learn, to appreciate the excitement of the moment and the responsibility that comes with the stage that is the NBA Playoffs. Antetokounmpo’s game is no longer about potential for the future. Instead, it’s about the possibilities he gives the Bucks in the present, something the Raptors learned the hard way as he ran them off the court. Now we’ll see if he can run them out of the playoffs.